Plug retaining plate for lock cylinders



Feb. 1, 1949- H. E. S'QREF ET AL 2,460,474

PLUG RETAINING PLATE FOR LOCK CYLINDERS Filed July 18, 1947 I INV NTO By mag? I 777(9k11dl4 7?)01MZL Patented Feb. 1, 1949 ram OFFICE PEUG-RETAINING PLATE-FOR LOCK CYLINDERS Harry Scref-andDaniel 'J. Foete Milwaukee, ,Wis... assignors to :Master .Lock Company, Milwaukc'e, Wis, a corporaticn ofWisconsin Application July 18, 1947, Serial 'No. 761,-862

This invention relatesto improvements in plug retainingplatesifor lock cylinders.

In certain types of locks thebody or casing contains -,a cylinder assembly into which the lock akey is inserted for operating the lock. The cylinder assemblydncludes' a pin-carrying shell having .revolubly mounted therein a cylindrical plug which receives thekey forthe purpose of actuating the pins. In .conventional lock structures of theltype underconsideration the outer'end of 10 the lock:casing is closed-by. a plate having an .opening therein :registering with and of slightly .greatendiameter-than the cylindrical'plug of the .:cylinder assembly. In a construction of this .characteraxial displacement of the shellof the: cylinder assembly is prevented by a bottom'plate which v.loears against the endof i the shell, thereby holding the shell .butpermitting-the plug to'have va necessary limitedaxial movement relative to the shell. However,displacement of thep-lug and, undueaxialmovement thereof is prevented solely by-a Washer secured within a shouldered groove 'on an inner extended portion of the plug and bearing againstlthe inneriend of the shell.

In the conventional arrangements describedp .the washerserves as thesole instrumentality for 'holding the cylinder assemblyin its correct relationship and during continued manipulation of the lock and removal ofthe tight fitting key from "the lock plug, the was'heris subjectedto consider-' 'able stress and strain, and should the washer -eventually"become worn or defective, the inner plug'oithe cylinder assembly can slip entirely out of the shell and thus render the lock inoperative.

"With'further respect to theponventional lock structures 'ofthetype cited, the washer-retainingarrangem'ent between the plug and the shell is such that too little,.axial movement between 'the'plug-and shell is permitted which often .re- 'sultsin misalinement of'theplug holes with, relation "to the shell-carried pins, causing the pins to lee-blocked and wedged so'that proper operation ofth'e' lock mechanism is. impaired. Additionally, in the conventional'structurea'lock picking is possible, as "pressure may be put onto the pins to block them.

With 'all of the ,foregoing considerations in min'dyit is 'a primary object of thepresent inven tion to provide a plug-retaining plate for a lock cylinder which eliminates the objections men 5.3?

tioned in connection with conventional cylinder lock structures through the provision of a retaining plate construction which .bears on the outerend of the plug to ,prevent displacement .of

the plug relative .to the cylinder .shell while per 4 Claims. (Cl. Vii-1367) mitting slight desirable and necessary play of the shell relative to the axially fixed plug.

In lock constructions of the type under consideration, the keysengage the cylinder assembly plugs quite tightly, and considerable pull must .be exerted one. key in removing it longitudinally from the cylinder assembly, and it is therefore, a further object of the invention to'provide a lock cylinder retaining plate,-which, while firmly holding the plug against axial movement, permits the cylinder shellto find its ownalinement, thereby facilitating the action'of the lock pins and removal of the key.

- -Afurther object 'ofthe invention is to provid in a lock construction of the class-described, a

plug retaining plate which eliminates pressure,

strains and wear on the washer whichis interposed between the plug and shell of the cylinder assembly.

A furtherobject-of the'invention is'to provide a lock construction of such a nature that it is very difficult to pick the lock, as'it prevents pressure bein-g applied'to the pins inthe cylinder assembly for thepurpose of blocking thepins.

A further object of the invention is to provide a'lock construction of the class described wherein wedging and binding as between the plugand shellis eliminated and which facilitates operation and movement of the cylinder assembly.

A further object of the invention is to provide a plug-retaining'plate for a lock cylinder which is of very simple construction, is strong and durable, is inexpensive, and is well adapted for the purposes set forth.

With'the above and other objects in view, the invention consists of the improved plug-retaining plate for a lockcylinder and its parts and'combinations, asset forth in the claimaand all equivalents thereof.

In .the accompanying drawing which the same reference characters indicate the same parts in-all-of the views:

-Fig. 1 is=a longitudinal sectional view of a lock having the improved plug-retaining plate, parts being broken away and in section;

Fig..2-is a bcttom or outer end view of the lock as shown in Fig. 1; and

Fig. 3 is 'an. enlarged fragmentary detail sectional viewof the interiorof the lock assemblage showing i-thecylinder shell and plug and'the relation of the plug-retaining plate thereto.

While theinvention has'been.illustrated'as beingembodied inlet-padlock, it to be understood that the plug-retaining plate structure is applicable to cylinder locks generally and may be used, not only in connection with padlocks, but with door locks, automobile locks, and other types of cylinder locks.

Referring now more particularly to the drawing, the lock body or casing is indicated by the numeral 5, and the interior of the same has partitions and walls to define cavities for certain of the lock mechanisms. As is conventional in locks of this type, there is mounted in the body and extending outwardly of the inner or upper end thereof, a shackle 5 having an extension arm poltion 6 thereof extending into a cavity in the body 5 and being mounted on a shackle spring .1 to permit yielding reciprocatory movement of the shackle, when released, and swinging movement thereof. The shorter arm portion 5" of the shackle is adapted, for locking purposes, to enter another cavity in the body and to have a shouldered portion 3 thereof entered by a spring urged lock lever i i. The latter is set and released by means of the mutilated projecting inner end portion 9' of a slotted cylindrical plug 9 forming part of a cylinder assembly, which assembly also includes a slotted shell Hi. The shell it is of less length than the plug 9 and encloses the plug in a manner so that the plug may turn in the shell, with the shell being anchored against turning movement by a lateral extension portion on the shell, confined within a suitable recess therefor in the body 5. The slotted portions of the shell and shell extension id have reciprocatably mounted therein, against springs H, a series of pins 82 which, when the assemblage is locked, enter openings therefor in the plug 9 but which, when a proper key it is inserted into the slot l therefor in the plug, are disengaged from the plug holes so as to permit turning movement of the plug 9 relative to the shell 50 for causing the plug mutilated inner end 9 to operate the lever 1%.

From Figs. 1 and 3, it will be observed that an inner portion of the plug 9, just beyond the inner end of the shell iii, is provided with an annular groove or recess H5 in which there is seated a retaining ring or washer II. In prior said reduced opening 2| is extruded or pressed outwardly slightly so as to define an annular collar 22 for the opening 2| with the inner face of said collar forming an annular shoulder 23 on which the outer end of the plug 9 firmly seats. Obviously, the arrangement of the plate l8, as described, is such that the annular shoulder 23 engages the outer end of the plug 9 and prevents axial movement of the plug, thereby anchoring the plug against any possible axial displacement but permitting the surrounding shell I0 to axially shift, if necessary. The reduced opening 2| is sufiiciently large to easily receive the shank of the key iii. In practice, a key fits rather tightly within the plug H] in engagement with the operated pins l2 and to withdraw the kei [3 from the lock, considerable pull must be exerted on the key. By virtue of the present improvements, this may be done without straining the cylinder assembly and without imposing any stress on the washer ll because the plug 9 is in abutment with the shoulder 23 of the plate l8 which takes all longitudinal forces.

In the improved lock structure, considerable advantage is found in anchoring the plug 9 against longitudinal or axial movement and permitting the necessary slight axial'movement for pin alinement to be accomplished through the manufacture, is easily mounted on the lock body lock structures of the type under consideration,

a similarly positioned washer was the sole means for preventing axial displacement of the plug relative to the cylinder shell. However, as will hereinafter appear, in the present invention the washer ll simply forms an instrumentality for holding the plug 9 and shell together as a unit and reliance is not placed on the washer IT as the means for preventing axia1 displacement of one of the cylinder assembly members relative to the other. In actual practice, there should be slight play of the washer ll in its groove l6 so that the shellmay make its proper alinement relative to the plug for freer action of the pins !2 and facilitation of removal of the key 53.

In the present invention gerat importance is attached to a specially formed retaining plate 93 secured to the lower or outer end of the casing 5 and its association with the plug 9 of the cylinder assembly. Said plate 58 is secured to the lock body or casing 5 by any convenient means such as by rivets or pins l9. There is formed in the inner face of the plate 18 and concentric with the cavity for the shell Iii, a circular opening it of greater diameter than the lower or outer end of the plug 2 which projects thereinto. The plate opening'zil does not, however, extend entirely through the plate I 8, but the outer stock of the plate It is formed with a reduced opening 2! of less diameter than the adjacent end of the plug a and the metal of the plate l8 surrounding to form an integral part of the lock assemblage, and is well adapted for the purposes described.

What we claim as our invention is: I

1. In a lock having a casing with a cavity therein which opens through an end of the casing, a pin shell non-rotatably mounted in said cavity, a plug turnable within said shell, means connecting the shell and plug as a unit and permitting slight longitudinal movement of the shell relative to the plug, and an apertured plate secured to said end of the casing and engaging the outer end of the plug to hold it against longitudinal movement while permitting slight longi-, tudinal movement of the shell within said cavity.

2. In a lock having a casing with a cavity therein, a cylinder assembly operatively mounted within said casing cavity, said cylinder assembly including a shell and a key-receiving plug turnable within the shell, and a plate secured to said casing, an intermediate portion of said plate having a shouldered aperture therein in which'the outer end of said plug is seated and retained against outward longitudinal movement.

3. In a lock having a casing with .a cavity therein, a pin shell non-rotatably mounted in said cavity, a key-operated plug turnable within said shell and having its outer end extended beyond the outer end of the shell, means turnably connecting the shell and plug as a unit and permitting slight longitudinal movement of the shell relative to the plug, and an apertured plate secured to an end of the casing and engaging the extended outer end of the plug to hold it against longitudinal movement.

4. In a lock having a casing with a cavity therein, a pin shell non-rotatably mounted in REFERENCES CITED said cavity, a key-operated plug turnable within said shell and having its outer end extended beh following r f renc s are of r r 1 the yond the outer end of the shell, the shell being T139 Of t P te t: susceptible of slight reciprocatory movement UNITED STATES PATENTS relative to the plug for pin alining purposes, and

a plate secured to said casing, an intermediate Number Name Date portion of said plate having a shouldered open- 16,123 Schonwald July 1925 ing therein in which the outer extended end of 2,231,083 Nelson 28, 1942 the plug is seated and through which a key may 10 be inserted into said plug.

HARRY E. SOREF. DANIEL J. FOOTE. 

